36 



reproduced in fig. 3, where an end- termination of considerable size is 

 seen lying upon the sarcoplasma of a single muscular fibril. In this 

 instance a few short terminal side branches are given off which termi- 

 nate in simple bulbs, but they are not always present. Figure 4 also 

 represents a terminal ending of approximately the same variety as 

 that pictured in fig. 3. 



These forme of termination are comparatively common for the 

 type of fibre, but in fig. 5, we find another variety of less frequent 

 occurrence. In this particular instance the nerve filament ran for a 

 very long distance among the muscular bundles without change of 

 calibre or varicosity, and eventually made a curve at nearly a right 

 angle, and then, just past the bend, began to attenuate slowly, be- 

 coming finer and finer, until at some distance from the first turn it 

 made another, again at a right angle, and appeared very minute and 

 less well stained than it had been heretofore, then suddenly developed 

 an ill-stained end-expansion of pennate form, in which there were 

 blackened masses of deeper shade than the major part of the appa- 

 ratus, the whole ending with low powers being rather of a blackish-red 

 color. 



In neither of these varieties of end-apparatus is there any struc- 

 ture ascertainable, the less deeply stained ones showing only a homo- 

 geneous brown colored groundwork, the particles, contained, being 

 nearly black. 



The endings of both the second and third types (the first being 

 the simple bulb or non-striated muscular tissue), have been found 

 scattered through every portion of the ventricular wall, deeply as well 

 as superficially situated, but none very close to the endo- or peri- 

 cardial linings. In no. 2 of fig. 2 is represented a somewhat thicker 

 fibre than the varicose plexus usually has in it, but which has a single 

 varicosity upon it, and terminates in an expansion of simple pennate 

 form, and is hardly to be classed as belonging to the fibres of the 

 plexus, but rather to the more complicated terminations. 



Even more peculiar than the complex end-expansion is the pre- 

 sence of a very constant bulb, at least so far as our specimens show, 

 of rounded or oval form, and of considerable size lying in the path 

 of the nerve fibre arising from these complex end-apparatus, and 

 situated at some considerable, though varying distance from the end- 

 expansion. This apparently ganglionic body has been found in the 

 line of nearly every fibre that could be traced for any considerable 

 distance from the termination upon a muscular fibre. Mainly, they 

 are of smooth exterior, with the thread of the nerve fibre entering 



